Seawater Leak on Cooling System - Stumped - With pics

[jayrodoh]

86 4winns Horizon 190 with the 170 4 cyl and an Alpha 1 outdrive. Just this year I've noticed water in the bilge after use. Not a ton but I'm getting tired or sponging out after every trip. This is a new leak. If the boat sits in water without running, no water in the bilge. All bellows etc are less than 3 years old. Boat has the closed cooling system, no coolant leaks (marina already did the impeller and seals on the cam). Checked the voltage regulator, power steering cooler, exchanger lines, all dry.

The pic below shows water after running in my driveway at 1200 RPM fpr 15 min. No other part of the bilge is wet, just the rear. It doesn't appear that the raw water hose coming from the top is leaking. Any ideas? I have not been able to catch a drip, laid there for 20 min watching while it ran and nothing, came back 10 later and saw this. It is repeatable. The drain plug is in, so it's not water splashing in (flash made it look like sunlight coming through).

It's been fun lying near a fully warmed up running engine for 20 min at a time when it's 94 and humid as all.

Not alot of water but adds up on those 8 hour days.

Thanks guys!



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[solar7647]

Re: Seawater Leak on Cooling System - Stumped - With pics

Since its closed cooled your water is coming from only a few places.
1) The heat exchanger is cracked or the end caps are leaking and need new gaskets, they go bad over time and will leak.

2) The hose from the heat exchanger to the power fluid cooler is leaking.

3) The power steering cooler is cracked

4) The hose from the power steering fluid cooler to the exhaust ellbow is leaking

5) One of the rubber exhaust boots are leaking, they will dry rot over time.

6) The water intake hose from the drive to the voltage regulator is leaking

Run the boat and inspect the listed areas, since it only happens when the engine is running those are your only options. Let us know what you find out.

Since it is only in the rear I would start with the intake hose from the drive if it's cold water, it could be loose, cracked or ripped. The plastic tube that comes from the drive could also be cracked.

If it's warm water check the exhaust system for the leak.

 

[skargo]

Re: Seawater Leak on Cooling System - Stumped - With pics

Had this problem twice. Once it was a pump issue, warped plastic. The most recent a couple weeks ago was a bad gasket on one of my heat exchanger's end caps. Made a gasket out of cork and used perfect seal on it and it's good to go.

 

[stonyloam]

Re: Seawater Leak on Cooling System - Stumped - With pics

it's 94 and humid as all.

Condensation from the cold seawater water inlet fitting?

 

[jayrodoh]

Re: Seawater Leak on Cooling System - Stumped - With pics

Condensation from the cold seawater water inlet fitting?

I thought about that, the metal lines do have condensation on them, but wouldn't be enough on the day trips were I get about a gallon in the bildge.

With the water only being in the back, I will take another look at the exchanger cap and the supply line from the drive tomorrow. Power steering cooler and regulator lines are dry.

 

[solar7647]

Re: Seawater Leak on Cooling System - Stumped - With pics

I thought about that, the metal lines do have condensation on them, but wouldn't be enough on the day trips were I get about a gallon in the bildge.

With the water only being in the back, I will take another look at the exchanger cap and the supply line from the drive tomorrow. Power steering cooler and regulator lines are dry.

Were you able to tell if the water was warm or cold? It will help figure out best place to look.

 

[jayrodoh]

Re: Seawater Leak on Cooling System - Stumped - With pics

Were you able to tell if the water was warm or cold? It will help figure out best place to look.

Didn't think to check.

Nice boat BTW, next will be a mid/late 80's Sundowner of that size. Perfect combo and the 4winns of that era are timeless to me.

 

[solar7647]

Re: Seawater Leak on Cooling System - Stumped - With pics

Didn't think to check.

Nice boat BTW, next will be a mid/late 80's Sundowner of that size. Perfect combo and the 4winns of that era are timeless to me.

Thanks for the comment on the boat. It was a lot of work! Just finished the project with the switching of the 3.7 to a 4.3. I agree with you that the design of boats during that time are timeless. I like them a lot better then newer designs, they also seem better built and easier to custimize to your liking.

 

[jayrodoh]

Re: Seawater Leak on Cooling System - Stumped - With pics

Bad post

 

[jayrodoh]

Re: Seawater Leak on Cooling System - Stumped - With pics

Kind of old now but I thought I should update with the fix in case it helps another.

Our last trip ended 10 yards from the dock with a nice growling noise. Once I got it home and pulled the drive, I was greeted with a bellow full of water. Water was getting in there and must have been working its way through the bearing while running, therefore creating my "mystery leak" while running it on muffs on the trailer. Explains why there was no water when it would just sit in the water.

Appears at first inspection that I goofed putting the gasket on this spring and it leaked